Purpose: To quantify the deformations of the femoro-popliteal (FP) arteries in patients
undergoing endovascular revascularization of the FP arterial tract and to compare the effects
of primary Nitinol stent implantation on the post-treatment arterial deformations with the
effects of percutaneous transluminal angioplasty (PTA).
Methods: 35 patients with peripheral arterial disease (PAD) were recruited for the study.
During endovascular interventions, angiographic images were acquired with the legs straight
and with a hip/knee flexion of 20°/70°. Image acquisition was performed before PTA for all
patients; after PTA for 17 patients that only underwent balloon angioplasty; and after primary
Nitinol stent implantation for the remaining 18 patients. A semi-automatic approach was used to reconstruct the 3D patient-specific artery models from 2D radiographs. Axial shortening and curvature changes in the arteries were calculated in-vivo for the calcified, ballooned and stented regions, as well as the regions that are distal and proximal to the diseased and treated segments.
Results: Leg flexion resulted in arterial shortening in all investigated segments. The ballooned
arteries exhibited higher shortening compared to their stented counterparts (post-balloon:
7.6% ± 4.9%; post-stent: 3.2% ± 2.9%; P: 0.004). Leg flexion also led to an increase in the
curvatures of all the segments of the FP arteries. Although there were no statistically
significant differences between the bending behaviors of the arteries treated with different
methods, 40% of the stented arteries exhibited arterial kinking during leg flexion.
Conclusion: The choice of the treatment method affects the post-interventional axial
deformations of the FP arteries, but does not influence their curvatures. While PTA results in
a more flexible artery, stents restrict the arteries’ shortening capabilities. Depending on the
anatomical position of the stents, this axial stiffening of the arteries may lead to chronic
kinking, which may cause occlusions and, consequently, impact the long-term success of the
procedure.